Discussion:
Lucas Horn mounting
(too old to reply)
Davey
2016-02-02 19:30:46 UTC
Permalink
I have a couple of Lucas Horns, just like these;

http://www.ebay.co.uk/itm/0RIGINAL-LUCAS-DUAL-TONE-12-VOLT-HORNS-/262260900504?hash=item3d0ff7c298:g:5acAAOSwk5FUvCP2

and I want to mount them on my headlamp bar. They are replacements for
a pair that disappeared long ago, so I know it is possible. I cannot
remember the details of how they were mounted, though. They are very
heavy.
They have a mounting bracket, which is composed of springy leaves,
right at the back end. Select the second image, and then zoom in, and
they are visible. The horns certainly look as though they are designed
to be supported off of these brackets, and presumably there should not
be anything under the body of the horn, to allow the body top to vibrate
properly, and produce the very loud lovely sound that they do. The
problem is, that all the weight of the horn will be cantilevered off
these, and that will surely lead to premature failure of the brackets,
even if I can devise some way of clamping them in place so that the
weight doesn't just make them rotate forward around the headlamp bar.
Does anybody know how these should be mounted? Were they originally
designed to be mounted on their sides, so that the force of their
weight was in a different direction, with the mounting bolts in the
same vertical plane?
Or should I just ignore these attached brackets, and make up a more
solid support?

Any help welcome.
--
Davey.
Indy Jess John
2016-02-02 22:40:30 UTC
Permalink
Post by Davey
I have a couple of Lucas Horns, just like these;
http://www.ebay.co.uk/itm/0RIGINAL-LUCAS-DUAL-TONE-12-VOLT-HORNS-/262260900504?hash=item3d0ff7c298:g:5acAAOSwk5FUvCP2
and I want to mount them on my headlamp bar. They are replacements for
a pair that disappeared long ago, so I know it is possible. I cannot
remember the details of how they were mounted, though. They are very
heavy.
They have a mounting bracket, which is composed of springy leaves,
right at the back end. Select the second image, and then zoom in, and
they are visible. The horns certainly look as though they are designed
to be supported off of these brackets, and presumably there should not
be anything under the body of the horn, to allow the body top to vibrate
properly, and produce the very loud lovely sound that they do. The
problem is, that all the weight of the horn will be cantilevered off
these, and that will surely lead to premature failure of the brackets,
even if I can devise some way of clamping them in place so that the
weight doesn't just make them rotate forward around the headlamp bar.
Does anybody know how these should be mounted? Were they originally
designed to be mounted on their sides, so that the force of their
weight was in a different direction, with the mounting bolts in the
same vertical plane?
Or should I just ignore these attached brackets, and make up a more
solid support?
Any help welcome.
The P4 Rover had horns with mountings like that. they were mounted
sideways either side of and behind the radiator with two fixing bolts.
The spring style mounting was simply to accommodate vibration without
metal fatigue. The fixing method pulled on the top mounting hole and
pushed on the bottom one.

I can't imagine the fixing lasting long if the fixing holes are
horizontal rather than vertical, so if you want to mount them on a
headlamp bar, you are looking for a clamp with a vertical bar to which
the mounting bracket of each horn bolts with one hole above the other.
Also the make and break contact will not work so well if the horn is
mounted horizontal. It is not designed for that orientation.

It might look best if the one vertical mounting was central, with one
horn pointing left and the other right. The alternative is two
verticals with the horns pointing towards each other.

One thing you might like to think about is how weatherproof the horns
are. The Rover ones were positioned under the bonnet out of the way of
rain and spray. On a headlamp bar they will be at the mercy of the
weather, and if they point forwards they will fill with rain as you
drive on rainy days. Pointing sideways they are still at the mercy of
wind-borne rain when the car is stationary. The electrics inside won't
survive long before corroding. I suspect you are going to be faced with
a decision of whether to have these horns as a working set out of sight,
or a pretty chrome set in full view which are for decoration only.

Jim
Davey
2016-02-03 00:52:44 UTC
Permalink
On Tue, 02 Feb 2016 22:40:30 +0000
Post by Indy Jess John
The P4 Rover had horns with mountings like that. they were mounted
sideways either side of and behind the radiator with two fixing
bolts. The spring style mounting was simply to accommodate vibration
without metal fatigue. The fixing method pulled on the top mounting
hole and pushed on the bottom one.
Now that all makes sense, and matches one of my thinkings. Since I
never had to worry about them, I never paid much attention to their
mounting method.
Post by Indy Jess John
I can't imagine the fixing lasting long if the fixing holes are
horizontal rather than vertical, so if you want to mount them on a
headlamp bar, you are looking for a clamp with a vertical bar to
which the mounting bracket of each horn bolts with one hole above the
other.
Hmm, I see what you mean. That would be not too difficult to make up,
but is not how they were originally sitting.
Post by Indy Jess John
Also the make and break contact will not work so well if the
horn is mounted horizontal. It is not designed for that orientation.
The original ones were horizontal, and sounded really good.
When I tested these replacement ones after purchase, I sat them
horizontally on my car's engine compartment bodywork near the battery,
and they were LOUD, so what possibly better operating conditions might
be like, I can't imagine! I think that there may be effectively no
aural problem in mounting them horizontally, even if they were designed
as you say, for vertical mounting.
Post by Indy Jess John
It might look best if the one vertical mounting was central, with one
horn pointing left and the other right. The alternative is two
verticals with the horns pointing towards each other.
I am thinking more of a central post, with one horn mounted on each
side, or two posts a distance apart. This is in no way yet thought
through, though. (Say that when drunk).
Post by Indy Jess John
One thing you might like to think about is how weatherproof the horns
are. The Rover ones were positioned under the bonnet out of the way
of rain and spray. On a headlamp bar they will be at the mercy of
the weather, and if they point forwards they will fill with rain as
you drive on rainy days. Pointing sideways they are still at the
mercy of wind-borne rain when the car is stationary. The electrics
inside won't survive long before corroding. I suspect you are going
to be faced with a decision of whether to have these horns as a
working set out of sight, or a pretty chrome set in full view which
are for decoration only.
Jim
The ones that were there originally had been there for many, many
years, and still worked fine. Early photos of the car from 1948 show
them, and my intention is to restore the original 'face' of the car.
They had a mesh in the throat, which might have acted as water
protection as well as a stone guard. The mesh was much finer than those
in the e-bay ad. My replacements don't have that (yet), so your point
is valid.

And £225 for the pair is silly money, they go, chromed, for more like
£70-£100. Those do look good, though.

Thanks for confirming the mounting setup.

This is a long-term project, so don't expect any updates soon. I'm
gathering information before deciding what to do.
--
Davey.
Indy Jess John
2016-02-03 08:46:14 UTC
Permalink
Post by Davey
On Tue, 02 Feb 2016 22:40:30 +0000
Post by Indy Jess John
The P4 Rover had horns with mountings like that. they were mounted
sideways either side of and behind the radiator with two fixing
bolts. The spring style mounting was simply to accommodate vibration
without metal fatigue. The fixing method pulled on the top mounting
hole and pushed on the bottom one.
Now that all makes sense, and matches one of my thinkings. Since I
never had to worry about them, I never paid much attention to their
mounting method.
Post by Indy Jess John
I can't imagine the fixing lasting long if the fixing holes are
horizontal rather than vertical, so if you want to mount them on a
headlamp bar, you are looking for a clamp with a vertical bar to
which the mounting bracket of each horn bolts with one hole above the
other.
Hmm, I see what you mean. That would be not too difficult to make up,
but is not how they were originally sitting.
Post by Indy Jess John
Also the make and break contact will not work so well if the
horn is mounted horizontal. It is not designed for that orientation.
The original ones were horizontal, and sounded really good.
When I tested these replacement ones after purchase, I sat them
horizontally on my car's engine compartment bodywork near the battery,
and they were LOUD, so what possibly better operating conditions might
be like, I can't imagine! I think that there may be effectively no
aural problem in mounting them horizontally, even if they were designed
as you say, for vertical mounting.
Post by Indy Jess John
It might look best if the one vertical mounting was central, with one
horn pointing left and the other right. The alternative is two
verticals with the horns pointing towards each other.
I am thinking more of a central post, with one horn mounted on each
side, or two posts a distance apart. This is in no way yet thought
through, though. (Say that when drunk).
Post by Indy Jess John
One thing you might like to think about is how weatherproof the horns
are. The Rover ones were positioned under the bonnet out of the way
of rain and spray. On a headlamp bar they will be at the mercy of
the weather, and if they point forwards they will fill with rain as
you drive on rainy days. Pointing sideways they are still at the
mercy of wind-borne rain when the car is stationary. The electrics
inside won't survive long before corroding. I suspect you are going
to be faced with a decision of whether to have these horns as a
working set out of sight, or a pretty chrome set in full view which
are for decoration only.
Jim
The ones that were there originally had been there for many, many
years, and still worked fine. Early photos of the car from 1948 show
them, and my intention is to restore the original 'face' of the car.
They had a mesh in the throat, which might have acted as water
protection as well as a stone guard. The mesh was much finer than those
in the e-bay ad. My replacements don't have that (yet), so your point
is valid.
And £225 for the pair is silly money, they go, chromed, for more like
£70-£100. Those do look good, though.
Thanks for confirming the mounting setup.
This is a long-term project, so don't expect any updates soon. I'm
gathering information before deciding what to do.
Good luck with it.

You have to bear in mind that my only experience of this type of horn is
from a 1956 Rover which I owned in 1965 (and somebody stole it and wrote
it off on a roundabout so I had less than a year's ownership. I can't be
absolutely certain that the Rover ones were the same make as the ones
you are looking at.

The handbook called the Rover ones "Windtone Horns" if that helps. The
Rover ones were two different and complementary pitches (Doh and Soh)
and sounded brilliant together. Only one worked when I got the car, but
a bit of emery paper to clean the corroded contacts got the other one
working, which is why I worried about damp getting into yours.

One final thought - have you considered having yours mounted so that
they point down from the headlamp bar? It would certainly simplify the
mounting arrangement.

Jim
Davey
2016-02-03 10:40:09 UTC
Permalink
On Wed, 03 Feb 2016 08:46:14 +0000
Post by Indy Jess John
Good luck with it.
You have to bear in mind that my only experience of this type of horn
is from a 1956 Rover which I owned in 1965 (and somebody stole it and
wrote it off on a roundabout so I had less than a year's ownership. I
can't be absolutely certain that the Rover ones were the same make as
the ones you are looking at.
The handbook called the Rover ones "Windtone Horns" if that helps.
The Rover ones were two different and complementary pitches (Doh and
Soh) and sounded brilliant together. Only one worked when I got the
car, but a bit of emery paper to clean the corroded contacts got the
other one working, which is why I worried about damp getting into
yours.
One final thought - have you considered having yours mounted so that
they point down from the headlamp bar? It would certainly simplify
the mounting arrangement.
Jim
'Windtone' is the Lucas model name, so they were the same units. They
usually come in pairs as you describe.

I'll think about that mounting arrangement, thanks. It would certainly
deafen any small animals on the ground, although it would diminish
the effect for vehicles in front. When I eventually get them installed,
I'll post here (if there is still a 'here').

I had a P4 for a short while, but never got involved with the horns.
There used to be a black car in our 'gang', it was called Cholmondeley,
pronounced 'Chumley' of course, and it was available to anybody whose
other car(s) was/were temporarily hors de combat, and who needed
transport. The purchase price was always £100 (this was back in the
'70s). It got lost over time, nobody knows where the last owner and the
car are now.
--
Davey.
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